From the preview:
The Uthuk Y’llan are a race twisted by their unholy alliance with the demonic realm. They have not been seen in Terrinoth since the First Darkness, when a horde led by Llovar Rutonu rampaged across the kingdoms of Elves, Dwarves, and Men. They came from the Ru Darklands, where their foul touch turned what was once green brown and sere. They did the same to the lands they conquered, turning them into blackened wastes, slaughtering or taking prisoner any who dared cross their path. It was only the heroism of Timmerran Lokander that saved the world, when he slew Llovar at the Battle of the Locusts. The threat of the Uthuk soon faded into memory, and memory into legend.
You can expect this set on store shelves sometime in Q4 of this year.